COPENHAGEN, Denmark, Dec. 18 (UPI) — World leaders took a “meaningful and unprecedented” step in Denmark Friday by striking a voluntary agreement to fight global warming, U.S. President Obama said.

Mitigation, transparency and financing “formed the basis of a common approach” the United States and its partners embraced, Obama told reporters.

The agreement, while non-binding, provides the “foundation for global action to confront climate change for years to come,” Obama said before leaving Denmark to return to Washington to try to beat a predicted 12-inch snowfall.

“Today we made meaningful and unprecedented breakthrough here in Copenhagen,” Obama said. “For the first time in history, all major economies came together to accept responsibility for their actions” in global warming.

The agreement, which Obama said could lead to something more binding in the future, is structured so each nation will list its “concrete commitments” into the document’s appendix, and would be subject to international consultation and analysis.

“It (the agreement) will not be legally binding, but it will allow for each country to show to the world what they’re doing,” Obama said. “There’ll be a sense on the part of each country that we’re in this together.”

The mitigating efforts are part of a commitment to limit global temperature increases to no more than 2 degrees Celsius during the next decade.

U.S. officials said the deal includes also includes a commitment by wealthy nations to collect $100 billion a year in climate aid for poor nations by 2020.

Obama said he came to the U.N. conference guided by the principle that “whatever commitment we make, we make sure that they’re commitments we can keep.”

Anticipating criticism from environmental organizations about the lack of a binding treaty such as the Kyoto Protocol or more stringent requirements on individual countries, Obama said he, too, wanted something more binding, “but that wasn’t going to be achievable at this conference.”

“The most important thing I think we can do at this point is to build some trust” between developed and developing countries and “get to the point where everybody recognizes that we all have to move forward together.”